Biomedical subjects

Ernesto Pozzi

Publications and source records attributed to Ernesto Pozzi.

11 recordsLinked to original sources

PubMed2006

Expression of receptor for advanced glycation end products in sarcoid granulomas.

RATIONALE: The receptor for advanced glycation end products (RAGE) engages a number of ligands implicated in inflammatory processes. The RAGE coding gene maps to the 6p21.32 region, close to the genes DRB1 and BTNL2, which are associated with sarcoidosis. OBJECTIVES: We investigated a possible implication of RAGE in sarcoid granulomas. METHODS: RAGE and major ligands (N-epsilon-carboxy-methyl-lysine [CML], S100A12, and S100B) expression was investigated by immunostaining of 99 paraffin-embedded biopsies of sarcoid tissues, and expression patterns were determined. Among the three RAGE gene single-nucleotide polymorphisms investigated, -374 T/A was selected, characterized in terms of transcriptional effect (immunocytochemistry and real-time polymerase chain reaction), and its frequency was determined in DNA extracted from biopsies. MEASUREMENTS AND RESULTS: RAGE, CML, S100A12, and S100B immunoreactivity was observed in all sarcoid granulomas, although at different intensities. The degree of RAGE expression significantly correlated with the degree of S100A12 expression. The -374 TT/AT genotypes, associated with higher RAGE transcriptional activity, were more frequent in the sarcoidosis biopsy group than in control subjects, and the association was confirmed in a second, independent series of 101 patients with sarcoidosis. CONCLUSIONS: We showed the association of RAGE and its ligands with sarcoidosis and suggest that an intrinsic genetic factor could be in part involved in its expression. In Italian patients, the -374 T/A polymorphism seems to be significantly associated with this disease.

Adolescent↗

PubMed2006

Foxp3 expressing CD4+ CD25+ and CD8+CD28- T regulatory cells in the peripheral blood of patients with lung cancer and pleural mesothelioma.

The role of T regulatory (Treg) cells in human cancer has not yet been clarified. We assessed the presence and function of CD4+ and CD8+ Treg cell subsets in the peripheral blood of patients with lung cancer (LC) and pleural mesothelioma (PM). We found a low but significant increase in the number of CD4+ T cells with phenotype and functional features of Treg cells in LC patients compared to normal healthy controls (NHC). Furthermore, total CD4+ T cells from LC patients proliferated less than cells from controls, suggesting that the increase in the CD4+ Treg cell pool has functional importance. LC patients also showed an expansion of the CD8+CD28- T cell subset and these cells expressed Foxp3 mRNA, as recently observed in alloantigen-specific CD8+CD28- T suppressor cells. No variation of peripheral Treg cell subsets was found in patients with PM, a disease with a predominantly localized nature. However, the lack of correlation between cancer stage and the number or the function of peripheral Treg cells in LC patients refuted the hypothesis that these cells are involved in tumor spreading. A possible involvement of the peripheral Treg cell pool in cancer development and/or in inducing systemic immunosuppression in LC patients can be hypothesized.

Aged↗

PubMed2005

SP-A binds alpha1-antitrypsin in vitro and reduces the association rate constant for neutrophil elastase.

BACKGROUND: Alpha1-antitrypsin and surfactant protein-A (SP-A) are major lung defense proteins. With the hypothesis that SP-A could bind alpha1-antitrypsin, we designed a series of in vitro experiments aimed at investigating the nature and consequences of such an interaction. METHODS AND RESULTS: At an alpha1-antitrypsin:SP-A molar ratio of 1:1, the interaction resulted in a calcium-dependent decrease of 84.6% in the association rate constant of alpha1-antitrypsin for neutrophil elastase. The findings were similar when SP-A was coupled with the Z variant of alpha1-antitrypsin. The carbohydrate recognition domain of SP-A appeared to be a major determinant of the interaction, by recognizing alpha1-antitrypsin carbohydrate chains. However, binding of SP-A carbohydrate chains to the alpha1-antitrypsin amino acid backbone and interaction between carbohydrates of both proteins are also possible. Gel filtration chromatography and turnover per inactivation experiments indicated that one part of SP-A binds several molar parts of alpha1-antitrypsin. CONCLUSION: We conclude that the binding of SP-A to alpha1-antitrypsin results in a decrease of the inhibition of neutrophil elastase. This interaction could have potential implications in the physiologic regulation of alpha1-antitrypsin activity, in the pathogenesis of pulmonary emphysema, and in the defense against infectious agents.

Enzyme Activation↗

PubMed2005

Exacerbations as a starting point of pro-active chronic obstructive pulmonary disease management.

Chronic obstructive pulmonary disease (COPD) exacerbations could represent an opportunity for pro-active COPD management rather than mere treatment if previously unknown disease is discovered; the extent of underdiagnosis and undertreatment of COPD in patients attending an emergency department (ED) with an exacerbation is not known. During 2002, we recalled 131 COPD patients in stable conditions, 4-8 weeks after they had attended the ED or been discharged from our University Hospital (North-West of Italy). Information on diagnosis and management prior to the ED attendance were collected; spirometry and arterial blood gas analyses were performed. One-third of patients had never been diagnosed and treated even though 83% of them had moderate-to-very-severe COPD and about 30% already had respiratory failure. Only 20% had received information on the nature of the disease and none had received a written action plan. Only 60% were receiving long-acting bronchodilators and 41% of patients with respiratory failure were receiving long-term oxygen. A substantial number of undiagnosed and untreated patients with moderate-to-very-severe COPD came to our attention through an exacerbation. This enforces the importance of exacerbations as the starting point of pro-active COPD management and of the ED as a valuable sentinel to identify this subset of patients.

Acute Disease↗

PubMed2005

NOD2/CARD15 gene polymorphisms in idiopathic pulmonary fibrosis.

BACKGROUND: Micro-organisms, behaving in a non-infectious fashion, may be among the exogenous factor(s) believed to trigger idiopathic pulmonary fibrosis (IPF). One possible strategy to identify an individual's susceptibility to such microbial triggers, which are likely to be ubiquitous, is to investigate the molecular processes involved in their recognition. NOD2/CARD15 is a specific pattern recognition receptor protein, whose genetic variants have been previously associated with susceptibility to Crohn's disease. AIM: The aim of this work was to determine the frequencies of the three major NOD2/CARD 15 gene mutations (R702W, G908R and 1007fsinC) in a series of 76 subjects affected by IPF, and to compare them with those found in three groups of controls: a group with sarcoidosis (a disorder in which an involvement of the NOD2/CARD15 gene has already been investigated and rejected in different ethnic groups; 67 subjects) and two groups of healthy subjects (218 and 208 subjects, respectively), matched for gender, age, and ethnicity. RESULTS: We found no differences in frequencies of NOD2/CARD15 gene polymorphisms among the four groups investigated. CONCLUSION: We conclude that the NOD2/CARD15 gene is not likely to be involved in susceptibility to IPF in Italians.

Aged↗

PubMed2004

Regulatory CD4+CD25+ T cells in the peripheral blood of lung transplant recipients: correlation with transplant outcome.

BACKGROUND: The subset of CD4+CD25+ regulatory T cells, recently identified in humans, may play a central role in the regulation of immune tolerance to graft survival. METHODS: This study assesses the frequency and functional profile of CD4+CD25+CD69- cells in the peripheral blood of lung transplant recipients (>3 years from transplantation), 10 of whom were in a stable clinical condition and 11 of whom demonstrated chronic rejection (bronchiolitis obliterans syndrome). We also studied a group of seven healthy subjects. RESULTS: The frequency of CD4+ T cells expressing CD25 (CD4+CD25+) and the highest levels (CD25) were lower in patients with bronchiolitis obliterans syndrome compared with healthy subjects and subjects in a stable clinical condition (P < or = 0.01). Purified CD4+CD25+ cells exhibited a regulatory functional profile in vitro: they were hyporesponsive, suppressed the proliferation of CD4+CD25- cells, and produced interleukin-10. CONCLUSION: These results provide in vivo evidence that peripheral CD4+CD25+ T cells may represent an important regulatory subset in lung transplantation.

Adult↗

PubMed2004

Assessment of emphysema in COPD: a functional and radiologic study.

OBJECTIVES: A combination of functional measurements reflecting a decrease in maximum flow, a degree of lung hyperinflation, the relationship between maximum inspiratory and expiratory flows, bronchodilator response, and diffusing capacity of the lung for carbon monoxide (DLCO) was used to quantify the extent of emphysema, as assessed by high-resolution CT (HRCT) scanning. DESIGN: Forced inspiratory and expiratory spirometry, lung volumes, reversibility test, and single-breath diffusing capacity were assessed before and after inhaling albuterol, 200 microg. Relationships between lung function variables and emphysema extent, as determined by HRCT scanning, were tested by univariate and multivariate analyses. SUBJECTS: Thirty-nine COPD outpatients with moderate-to-severe obstruction. MEASUREMENTS AND RESULTS: Emphysema extent, as assessed by HRCT scanning, ranged from 18 to 70%. All of the lung function parameters that were studied, except for the change in FEV1 percent predicted after salbutamol inhalation, correlated significantly with the extent of emphysema (r2 range, 0.19 to 0.44). Functional residual capacity, forced expiratory flow at 50% of FVC/forced inspiratory flow at 50% of FVC, DLCO/alveolar volume ratio, and bronchodilator-induced change in FEV1/FVC ratio were the only variables retained by stepwise multiple regression analysis. The multiple regression model explained 71% of the variability of emphysema extent measured by HRCT scanning. CONCLUSIONS: The combination of lung function measurements reflecting lung hyperinflation, bronchial collapsibility, lung diffusing capacity, and bronchodilator response provides a good estimate of the extent of emphysema, as evaluated by HRCT scanning. These data suggest that pulmonary function tests are useful in assessing and monitoring parenchymal damage in COPD patients.

Aged↗

PubMed2004

BAL cytokine profile in different interstitial lung diseases: a focus on systemic sclerosis.

BACKGROUND AND AIM: Fibrosing alveolitis develops in up to 80% of systemic sclerosis patients (SSc) but progression to end stage fibrosis occurs in about 15% of cases. Mechanisms leading to the process remain mostly unknown. We compared cytokine profiles of broncho-alveolar lavage fluids (BAL-f) from patients with SSc associated interstitial lung disease (SSc-ILD) (n. 34), idiopathic pulmonary fibrosis (IPF) (n. 13), stage II sarcoidosis (n. 14) and 9 controls. METHODS: Interleukin (IL) 8, monocyte chemoattractant protein 1 (MCP-1), gamma-interferon (IFN-gamma), IL12, IL18 and IL10 and transforming growth factor-beta (TGF-beta) were assessed by ELISA in concentrated BAL-f. RESULTS: Levels of IL8 and MCP-1 were significantly elevated in SSc-ILD and in IPF as compared with controls (Mann Whitney test p < 0.05), while MCP-1 values were significantly lower in SSc-ILD than in IPF. A significant correlation between neutrophils and IL8 levels (p = 0.047), as well as between eosinophils and MCP-1 levels (p = 0.004) was also observed. IFN-gamma levels were slightly higher than normal only in sarcoidosis (p = 0.06), whereas IL12 levels increased both in sarcoidosis and SSc-ILD (p < 0.05). No differences were found in IL18 and TGF-beta levels. Finally, IL10 levels were higher in SSc-ILD and sarcoidosis than in controls and IPF (p < 0.05). CONCLUSION: BAL-f cytokine profile differentiates ILD associated with SSc from IPF. The lower expression of MCP-1 and the higher expression of the anti-fibrotic IL12 and the anti-inflammatory IL10, observed both in sarcoidosis and in SSc-ILD, could account for the better prognosis of these ILDs. Further longitudinal studies are required to confirm whether a different cytokine phenotype may be considered predictive of clinical outcome in SSc-ILD.

Adult↗

PubMed2003

Complement receptor 1 gene polymorphisms are associated with idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic, fibrotic disorder underlain by aberrant wound healing of repeated lung injury. Environmental triggers and genetic background are likely to act as modifiers of the fibrotic response. Erythrocyte complement receptor 1 is a membrane protein mediating the transport of immune complexes to phagocytes. Three gene polymorphisms are related to the erythrocyte surface density of complement receptor 1 molecules, which in turn are related to the rate of immune complexes' clearance. There is evidence of association between sarcoidosis and the complement receptor 1 gene. We wondered whether IPF is associated with the complement receptor 1 gene alleles coding for a reduced molecule/erythrocyte ratio. We studied 74 patients and 166 control subjects. Three polymorphic sites of the gene, A3650G exon 22, HindIII RFLP intron 27, and C5507G exon 33, were analyzed and found to be in linkage disequilibrium. The GG genotype for the C5507G exon 33 polymorphism was significantly more common in patients with IPF than in control subjects (odds ratio = 6.232, 95% confidence interval = 2.198-18.419, p = 0.00023). The significant difference was found in both sexes. These findings agree with speculations on the role of the complement receptor 1 gene in idiopathic pulmonary fibrosis.

Aged↗

PubMed2002

Pharmacological analysis of signal transduction pathways required for mycobacterium tuberculosis-induced IL-8 and MCP-1 production in human peripheral monocytes.

Signalling cascades involved in chemokine production by human phagocytes following infection with Mycobacterium tuberculosis are still not defined. We used specific pharmacologic inhibitors to identify the signalling molecules which lead to interleukin (IL)-8 and MCP-1 production in human monocytes in response to M. tuberculosis infection. Inhibition of extracellular signal-regulated (ERK) or p38 mitogen-activated protein kinase by PD98059 and SB203580 respectively, significantly affected chemokine production. However, only the presence of both inhibitors completely blocked the release. A down-regulation of chemokine secretion was found in presence of inhibitors of protein kinase (PK)C and phospholipase C. Moreover, production depended on transcription activation via the nuclear factor-kappa B (NF-kappaB), as demonstrated by treatment with actinomycin D and caffeic acid phenethyl ester. In addition, activation of PKA and the phosphoinoside 3-kinase (PI-3k)/p70 ribosomal S6 kinase cascade was required to have maximal MCP-1 but not IL-8 production. In conclusion, this study provides evidence that multiple signal transduction pathways are involved in M. tuberculosis -induced chemokine secretion by human monocytes. Moreover, for the first time this report indicates that inhibitors of some signalling molecules are able to dissociate IL-8 from MCP-1 secretion. Differences in the regulatory pathways of chemokine production can potentially be exploited therapeutically.

Chemokine CCL2↗

PubMed2002

Complement receptor 1 gene polymorphisms in sarcoidosis.

Sarcoidosis is likely to result from exposure of genetically susceptible hosts to environmental agents. Erythrocyte (E) complement receptor 1 (CR1) is a membrane protein mediating the transport of immune complexes (ICs) to phagocytes, and at least three polymorphisms on the CR1 gene are related to erythrocyte surface density of CR1 molecules, in turn related to the rate of IC clearance from circulation. We hypothesized that sarcoidosis could be associated with increased frequency of the CR1 gene alleles coding for reduced CR1/E ratio. We studied 91 sarcoid patients and two control groups: 94 healthy volunteers and 71 patients with chronic obstructive pulmonary disease (COPD). Three polymorphic sites of CR1 gene, His1208Arg, intron 27 HindIII/RFLP, and Pro1827Arg, were analyzed. The three polymorphisms were in linkage disequilibrium. The GG genotype for the Pro1827Arg (C(5507)G) polymorphism was significantly associated with sarcoidosis in comparison to both control groups (odds ratio [OR] = 3.13; 95% confidence interval [CI] 1.49-6.69 versus healthy control subjects, and OR= 2.82, 95% CI 1.27-6.39 versus COPD control subjects). The same genotype was particularly associated to disease in females (OR = 7.05; 95% CI 3.10-16.61 versus healthy control subjects). These findings agree with speculations on the role of CR1 gene as a possible susceptibility factor.

Adult↗